1.2 What are constellations?
In the following video, Phillipa Smith explains what a constellation is and points out the most obvious ones to look for in the night sky.
Download this video clip.Video player: ou_futurelearn_orion_vid_1007.mp4
Transcript
JANET SUMNER:
There are loads of stars, and I can kind of see some patterns.
PHILLIPA SMITH:
Yep.
JANET SUMNER:
But what exactly is a constellation?
PHILLIPA SMITH:
Well, a constellation is just a group of stars, really. They were named during the ancient Greek ages, and some of the other ancient civilizations have also named them. And it’s just a way of identifying patterns in the sky. So they’d look up and see formations and then they’d make a name and sort of a little bit of a story around it, really, based on their gods or different things like that.
JANET SUMNER:
Well, I know Orion the hunter who’s over there.
PHILLIPA SMITH:
Yep.
JANET SUMNER:
So what are the kind of really obvious constellations that people could go out and look for?
PHILLIPA SMITH:
OK. So if Orion’s over there, then directly on the other side you can look for Ursa Major-- or the Plough, which is a small part of that-- also known as the Big Dipper.
JANET SUMNER:
Oh yes, that’s the one that looks like a pan.
PHILLIPA SMITH:
Yeah, you’re absolutely right. And if you have a look at the pan part, if you look to the top right star, if you carry on up, and that’s the North Star. That’s directly above the North Pole. So if you measure the angle between the horizon and the North Star, you can work out how far north you are.
JANET SUMNER:
So would people have used that to navigate then?
PHILLIPA SMITH:
Yeah, absolutely. The days before GPS and radar people would use this to navigate at night, sailors, things like that. Yep.
JANET SUMNER:
Is there another easy one to recognise?
PHILLIPA SMITH:
Another famous one is just above us, actually. Cassiopeia. It looks like a W or perhaps an M, depending on where it is in the sky.
JANET SUMNER:
Oh yeah, I got that.
PHILLIPA SMITH:
You can see that?
JANET SUMNER:
Yeah.
PHILLIPA SMITH:
So that’s the W right there.
JANET SUMNER:
Right. I know Orion.
PHILLIPA SMITH:
Yep.
JANET SUMNER:
I know the Big Dipper.
PHILLIPA SMITH:
Yep.
JANET SUMNER:
I’ve got Cassiopeia.
PHILLIPA SMITH:
Yep.
JANET SUMNER:
I’m now going to go away and learn all of the other constellations in the night sky.
PHILLIPA SMITH:
Fantastic.
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